Problem of the Pliocene/Pleistocene boundary in fresh-water deposits at Mizerna, West Carpathians

TheMizerna site (Polish Western Carpathians) is one of the most important Pliocene palaeobotanic sites in Central Europe. Its fresh-water deposits, laid down in a buried river valley, were studied in detail more than half a century ago in natural exposures and shallow boreholes, prior to partial drowning of the area by an artificial lake. The deposits yielded a very rich macrofossil plant collection elaborated in detail by Szafer (1954) who claimed that they represented a continuous succession of the Pliocene through Early Pleistocene plant communities. First palynological examination of the Mizerna deposits (by Oszast) was made more than half a century ago. Re-evaluation of stratigraphic and palaeoclimatic significance of macrofossil plant remains, along with a reassessment of palaeoenvironmental and sedimentary conditions during formation of the Mizerna fresh-water deposits, is in progress. This may help elucidate the problem whether the Mizerna sediments represent both the Pliocene and Early Pleistocene or, solely, the Pliocene successions